Postal stamp tracking system and method

ABSTRACT

A trackable postage stamp includes a first surface and a second surface opposite the first surface. The second surface is adapted to adhere to a piece of mail. The stamp also includes a passive tracking device including stamp identification (ID) information.

BACKGROUND

The present invention relates generally to postage stamps. Moreparticularly, the present invention relates to a system and method fortracking individual postage stamps.

Postage stamps are commonly used to pay for the service of delivering apiece of mail from one location to another. The stamps are affixed tothe piece of mail and the mail is dropped into a mailbox or other mailreceptacle for delivery.

In recent years, a few individuals have taken advantage of the anonymityof the postal system to deliver dangerous packages or harmfulsubstances. In one recent example, an individual mailed explosivedevices to unsuspecting victims. Little evidence as to the source of themail, much less the identity of the individual, was available. Inanother recent example, one or more persons mailed a harmful substanceto unwitting individuals. In this case, the letters were available toinvestigators but little information could be gleaned other than wherethe stamp had been canceled.

SUMMARY

The present invention provides a trackable postage stamp comprising afirst surface having information thereon and a second surface oppositethe first surface. The second surface is adapted to adhere to a piece ofmail. The stamp also includes a passive tracking device including stampidentification (ID) information.

In another aspect, the invention provides a stamp dispensing systemcomprising a plurality of stamps. Each stamp includes a tracking devicethat includes stamp ID information. A stamp dispenser is adapted tocontain and dispense the stamps and a reader is operatively associatedwith the stamp dispenser to read the stamp ID information when therelative position between the stamp and the reader changes. A databaseis operable to store the read stamp ID information.

In still another aspect, the present invention provides a method oftracking the use of a stamp. The method includes the steps of couplingtracking information to the stamp, the tracking information including astamp ID and dispensing the stamp to a customer. The method furtherincludes reading the tracking information as the stamp is dispensed, andstoring the stamp ID in a database.

Additional features and advantages will become apparent to those skilledin the art upon consideration of the following detailed description ofpreferred embodiments exemplifying the best mode of carrying out theinvention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the accompanying figuresin which:

FIG. 1 is a front view of a postage stamp including a radio frequencyidentification (RFID) device;

FIG. 2 is a front view of another stamp including a bar codeidentification device;

FIG. 3 is a front view of a stamp dispensing machine;

FIG. 4 is a partially broken away side view of the dispensing machine ofFIG. 3 including a reader;

FIG. 5 is a perspective view of a mailbox;

FIG. 6 is a partially broken away side view of the mailbox of FIG. 5including a reader;

FIG. 7 is a front view of a book of stamps including a bookidentification device; and

FIG. 8 is a flow chart illustrating the tracking of a single stamp.

DETAILED DESCRIPTION

With reference to FIG. 1, a typical postage stamp 10 is illustrated. Thestamp 10 includes a first surface 15 having an image imprinted thereon.A second surface 20 (shown in FIG. 4) opposite the first surface 15includes an adhesive that aids in the attachment of the stamp 10 to apiece of mail 25 such as a letter or a package. The stamp 10 alsoincludes a tracking device 30 attached to the first surface 15 of thestamp 10. The tracking device 30 is illustrated as a small square in thelower right-hand corner of the stamp 10. While many tracking devices 30are possible, a passive radio frequency identification (RFID) tag 33 isthe preferred device.

RFID tags are generally classified into two broad groups, passive andactive. Passive tags do not include a power supply of their own, whileactive RFID tags include a power supply such as a battery. Active RFIDtags are typically able to be read from greater distances when comparedto passive RFID tags. In addition, active tags can typically store andtransmit more information than can passive RFID tags. However, activeRFID tags are typically larger and more expensive then passive RFIDtags. In addition, active RFID tags have a limited life span due totheir need for an internal power supply.

RFID tags, whether passive or active, include an antenna and atransponder. The transponder may include memory (e.g., RAM, ROM, and/ornon-volatile memory (EEPROM)) as well as analog or digital circuitry.The antenna provides for the communication link between a reader and theRFID tag.

While active tags derive their power from a battery or other energystorage device, passive tags receive power from the field generated bythe reader. Passive tags generally rely on inductive coupling totransfer both power and data between the tag and the reader. Forinductive coupling to function, the reader must produce a stronghigh-frequency field. The antennae of the reader and the tag, when inclose proximity, establish a loosely connected “space transformer” whichallows for the transfer of power to the RFID tag. The power operates thetransponder circuitry, which transmits data to the reader if the RFIDtag is properly queried.

Many frequency ranges can be used to operate passive RFID tags. However,three ranges have emerged in the industry, with each range havingadvantages and drawbacks. The low frequency range (approximately 100-500kHz) allows for short to medium read ranges and is inexpensive tooperate. However, the relatively slow reading speed inhibits the use oflow frequency systems where many tags must be read quickly. Theintermediate range (approximately 10-15 MHz) allows for short to mediumread ranges, is potentially inexpensive, and provides for medium readingspeed. The high range (approximately 850-950 MHz and 2.4-5.8 GHz)provides for long read range and a high reading speed (e.g., 2 megabitsper second or faster). However, the high frequency RFID tags areexpensive to manufacture and may require a line-of-sight to be read. Assuch, the medium frequency range or the low frequency range arepreferable over the high frequency range.

In one construction, an RFID tag placed within the alternating magneticfield created by the reader draws energy from the magnetic field. Thisadditional power consumption can be measured remotely as a voltageperturbation at the internal impedance of the reader antenna. Theperiodic switching on and off of a load resistance at the tag thereforecauses voltage changes at the reader's antenna and thus has the effectof an amplitude modulation of the antenna voltage by the remote tag. Ifthe switching on and off of the load resistor is controlled by the tag'sstored data stream, then this data is transferred from the tag to thereader. This type of data transfer is called load modulation. Theprocess of load modulation creates amplitude modulated sidebandssymmetrically placed around the 13.56 MHz interrogation carrierfrequency.

Because the coupling between reader antenna and tag is relatively weakand the voltage change created by the tag leads to relatively poorsignal-to-noise ratios, reply code modulation with a subcarrier isutilized in most RFID chips. In this improved signalling method, thetag's data reply information is contained in a pair of backscatteredsidebands which are subsequently demodulated in the RF and basebandsignal processing sections of the reader to recover the tag's datastream. In ISO 15693 chips, for example, the subcarrier frequency isequal to 423.75 kHz (Fc/32) with either FSK or OOK modulation andManchester data coding. The achievable label data transfer rate is up toa relatively fast 26.48 Kbps.

Passive RFID tags 33 are preferred for many reasons including theirability to be manufactured in large quantities and at sizes of less than⅓ of a millimeter. In addition, passive RFID tags 33 can store 128 bits,256 bits or more data as required. Furthermore, passive RFID tags 33 canbe read from several feet away without a clear line of sight. This makesit possible to incorporate a reader 35 into a vending machine 40,mailbox 45, or other device that handles mail 25 or stamps 10. Onesuitable passive RFID tag is manufactured by XXXXX XXXX XXX of XXX, xx.

Passive RFID tags 33 can be made small enough to be essentially hiddenon the surface 15 or 20 of the stamp 10. Thus, while the tag 33 isrepresented as a small square on the surface 15 of the stamp 10, itshould be understood that the tag 33 could be smaller than illustratedand would be difficult to see. In other constructions, the RFID tag 33is attached to the second surface 20 of the stamp 10 to assure that itremains hidden from view or does not interfere with the image printed onthe front 15 of the stamp 10.

In another construction, illustrated in FIG. 2, the stamp 10 a includesa tracking device 30 in the form of a bar code 50 (e.g., micro bar code)printed on the surface 15 of the stamp 10. The bar code 50 can beprinted with the stamp image or during a separate printing step. Inaddition, the bar code can be hidden within the image on the stamp. Likethe RFID tag 33, the bar code 50 is able to store data related to thestamp 10 and convey that data whenever the stamp 10 passes near areading device. Unlike RFID, the bar code 50 requires a clear line ofsight between the reader and the bar code 50 in order for the data to beread. The line of sight can be provided using mirrors or lenses ifdesired. However, an opaque object between the bar code and the readercan inhibit or prevent reading of the bar code.

In addition to single stamps 10, the present invention is well-suited totracking stamps 10 sold in books 55 as illustrated in FIG. 7. The book55 includes a book tracking device 60 such as an RFID tag or a bar code.The tracking device 60 includes information that clearly identifies thebook 55. The tracking device 60 may also include data related to theindividual stamps 10 contained within the book 55.

The tracking devices 30, 60 may include different information dependingupon what type of product they are attached to. For example, whenattached to the single stamp 10, the tracking device 30 may includestamp identification information 65 that includes one or more of a dateof manufacture, a location of manufacture, a postage value, or anidentification number. The numbers may be combined and encrypted toprevent tampering or reading by unauthorized individuals. In theexample, a random number is combined with the other data and storedwithin the tracking device 30 as the stamp identification information 65or stamp identification number. The stamp identification number 65 isunique to the stamp 10.

In the example, the stamp identification number 65 is also stored in acentral database 70 along with the data that was used to make up the IDnumber 65. The data that makes up the stamp identification number 65 isparsed into its component parts such that the data can be used in thefuture if desired. It should be noted that the central database 70 neednot be a single database located within a single computer or computersystem. Rather, a network of several computers could be employed orseveral isolated computers could be used to house the data.

It should be clear to one of ordinary skill that many different forms ofstamp identification numbers are possible. For example, all of thedesired information could be combined mathematically into a singlenumber that identifies the stamp 10. The combination could be such thatthe useable data could be extracted from the single ID number using aseries of mathematical operations. In another construction, the stampidentification number consists of a series of numbers with each numberrepresenting a piece of data related to the stamp 10. In still anotherconstruction, no useful information is contained within the ID numberassigned to the stamp 10. Instead, the information is recorded in thecentral database 70 and associated with the stamp identification number.The stamp identification number acts as a license plate that identifiesthe stamp and guides the user to the related stored data. Thus, eachtime the stamp identification number is read, the desired information isrecorded in the central database 70 and associated with the correctstamp 10.

A book of stamps 55 may include a book identification number 75 that mayinclude similar data to that of the stamp identification number 65. Inaddition, book data may include the stamp identification information 65of each stamp 10 contained within the book 55. Again, the data could bemathematically combined into a single book identification number 75 ifdesired or could be represented by a series of numbers. In someconstructions, each book 55 is given a book identification number 75that does not represent any useful data but instead simply identifiesthe book 55. Useful data is recorded in the central database 70 andassociated with the book identification number 75. For example, the dateand place of manufacture could be recorded in the central database 70and associated with the book identification number 75 on the date thebook 55 is assembled. In addition, the stamp identification number 65 ofeach stamp 10 in the book 55 could be recorded in the database 70 andassociated with the book identification number 75, thus enabling thetracking of each stamp 10 as it is used. Thus, the book identificationnumber acts as a pointer to link the book to the desired stored data.

Turning to FIGS. 3 and 4, one vending machine 40 suited to dispensestamps 10 is illustrated. Stamps 10 are often dispensed from machines 40of this type as single stamps 10, in books 55 (often containing twentystamps or more), in sheets, or in rolls (often including 100 or morestamps). In addition, stamps 10 are dispensed in various denominationsfor use with different classes of mail 25 (e.g., post cards, letter sizeenvelopes, full size envelopes, padded envelopes and the like). As such,the typical vending machine 40 includes several selections that aredisplayed in windows 76. To make a selection, a purchaser inserts moneyand depresses a button 77 located beneath the window 76 that displaysthe desired product. It should be noted that rolls and sheets aretracked by the invention in much the same manner as books 55. As such,rolls and sheets, as well as other forms in which multiple stamps 10 aresold together, should be considered books 55.

FIG. 4 illustrates a dispensing chute 80 of the vending machine 40 ofFIG. 3. After the purchaser selects a product, the product is directedto the dispensing chute 80. The reader 35 disposed adjacent thedispensing chute 80 is able to read the tracking device 30, 60 attachedto the product being dispensed. The reader 35 can be an RFID transponderthat both queries and receives the data from an RFID tag 33, or a barcode reader that reads the bar code 50 as it passes. The product is thenremoved from the machine 40 by the purchaser and used as desired. Thereader 35 can include a storage device such as a hard disk drive 85 thatis able to store the data read from the product as it is dispensed. Whenthe machine 40 is replenished, the data can be downloaded for storage inthe central database 70. In another construction, the vending machine 40includes a wired or wireless data transmitter 90 suited to transmittingthe data periodically, or immediately after reading.

FIGS. 5 and 6 illustrate the typical mailbox 45 including a reader 35 a.The mailbox 45 includes a mail slot 95 that is sized to receive thetypical piece of mail 25. As the mail 25 is slid through the slot 95,the tracking device 30 is exposed to the reader 35 a and read. Inconstructions that use RFID tags 33, a single reader 35 a is able toread the tag 33 no matter the orientation of the envelope 25. Inconstructions that employ bar codes 50, two readers may be required, oneon the top of the slot 95 and one on the bottom of the slot 95. Thereader 35 a, or readers, can include a storage device such as a harddisk drive 85 a that is able to store the data read from the stamps 10.When the mail 25 is removed from the mailbox 45, the data can bedownloaded for storage in the central database 70. In anotherconstruction, the mailbox 45 includes a wired or wireless datatransmitter 90 a suited to transmitting the data periodically, orimmediately after reading.

Constructions that use RFID tags 33 are able to read multiple RFID tags33 substantially simultaneously as they are deposited in the mailbox 45.Thus, inserting several envelopes 25 at once will likely not defeat thesystem. However, a system that employs bar codes 50 and a single readermay only be able to read the bar code 50 if a single envelope 25 isdropped into the mailbox 45. Simultaneously depositing multipleenvelopes 25 into the mailbox 45 may cover one or more of the bar codes50 and would inhibit system function. If an envelope is sensed but theRFID tag or bar code is not read, the sensor could activate an indicatorthat would inform the postal worker that mail in that mailbox should becarefully examined.

The tracking devices 30, 60 work in conjunction with the centraldatabase 70 as illustrated in FIG. 8 to track stamps 10 as they movethrough the postal system. During or after the manufacture of the stamp10, the tracking device 30 is attached to the stamp. The tracking device30 includes, or is later programmed to include the stamp identificationinformation 65. Data regarding the stamp identification number 65 aswell as known data at the time of manufacturing is recorded in thecentral database 70. The data recorded in the central database 70 isparsed into usable segments such as the date and location of themanufacture of the stamp 10. In constructions that assign a singlenumber or a series of numbers to each stamp 10, the assigned numbers arerelated to the desired data in the database 70, thereby making the dataaccessible when needed. FIG. 8 illustrates two possible stampidentification numbers 65 a and 65 b. The first, 65 a includes usefuldata separated by hyphens, while the second 65 b includes a number thatconveys no information about the stamp 10 but rather serves to identifythe stamp 10 so that useful information can be stored within, orretrieved from the central database 70. In the case of the second IDnumber 65 b, the ID number 65 b acts as a pointer in the database. TheID number 65 b allows the user to recover the useful information bysimply retrieving the data associated with the ID number 65 b.

When the stamp 10 is dispensed, the stamp identification number 65 isread. The date and location of the sale is stored or transmitted to thedatabase 70 for storage. In addition, a surveillance camera may bepositioned to capture an image of the purchaser as the stamp 10 is beingdispensed. This data can also be stored in the database 70 (e.g., in the“Sold To” column) and associated with the particular stamp 10 that waspurchased.

When the stamp 10 is used, it is again scanned and data regarding thedate and place the stamp 10 was placed in the postal system is recorded.The scanned data is stored within the database 70 for later analysis ifnecessary. Again, in many locations, it is also possible to capture animage of the mailer and store that image in the database 70 (e.g., inthe “Used By” column).

The process just described is similar to the process that occurs when abook 55 of stamps is involved. Each book 55 includes a bookidentification number 75 that either directly conveys information orsimply identifies the book 55 to allow for the storage and retrieval ofbook information in the central database 70. In addition, each stamp 10within the book 55 includes a stamp tracking device 30 including stampidentification information 65.

When the book 55 is manufactured, the book identification number 75along with book data is recorded in the central database 70. The bookdata is similar to the stamp data with the addition of a list of stampidentification numbers 65 identifying the stamps 10 contained within thebook 55. By storing this data, it is possible to track the individualstamps 10 by first tracking the manufacture and sale of the book 55,followed by the use of the individual stamps 10.

Thus, when the book 55 is sold, the date and location of the sale, alongwith an image of the purchaser can be associated with the stampidentification number 65 for each stamp 10 in the book 55. When thestamps 10 are used, they are tracked and data is recorded in the sameway as it is with individual stamps 10.

The data within the database 70 can be analyzed to look for patterns orparticular individuals based on the stamps 10 that they use. Forexample, any stamp 10 that is deposited in the postal system more than acertain distance (e.g., seventy-five miles) from where it is purchasedcould be flagged as suspect, if this is deemed an unusual activity.

In addition, where the postal service is used for questionable orimproper activities and the stamp 10 used is available, informationregarding the purchase location, deposit location, as well as an imageof the purchaser and the user may be available to identify the purchaseror user.

In some constructions, stamps 10 that are not properly read are flaggedas suspect. In some situations, an error with the reader 35 may causethe system to miss a stamp 10. Furthermore, it is possible for someoneto tamper with the stamps 10 in an effort to defeat the system. Todetect these situations, the mailbox 45 not only reads the trackingdevice 30 as the envelopes 25 are deposited in the mailbox 45, but alsocounts the number of envelopes 25. If the number of envelopes 25 doesnot match the number of tracking devices 30 read, the mailbox 45 isflagged and all of the stamps 10 are re-read until the unread stamps 10are discovered. In another construction, the mailbox 45 reads the stamps10 and provides a total count. The postal service employee or a machinethen counts the number of stamps 10 to determine if any of the stamps 10were not read. If one or more were not read, the stamps 10 are re-readuntil the unread stamp 10 or stamps 10 is discovered, or the mail itselfis carefully examined. In this manner, undesirable tampering, or errorsin the reading process can be detected and accounted for no matter whattype of tracking device 30 is employed.

Thus, any tampering can be detected before a piece of mail 25 isdelivered. As such, useful information can still be gleaned from thestamp 10, and suspicious mail can be individually examined.

Although the invention has been described in detail with reference tocertain preferred embodiments, variations and modifications exist withinthe scope and spirit of the invention as described and defined in thefollowing claims.

1. A trackable postage stamp comprising: a first surface; a secondsurface opposite the first surface and adapted to adhere to a piece ofmail; and a passive tracking device without an onboard power supply andincluding stamp identification (ID) information, wherein the passivetracking device includes a radio frequency identification device (RFID).2. (canceled)
 3. (canceled)
 4. The postage stamp of claim 1, wherein thestamp ID information includes encrypted data corresponding to at leasttwo of a date, a location, a postage value, and a unique designation. 5.The postage stamp of claim 4, wherein encrypted data are combined to atleast partially yield the stamp ID information.
 6. The postage stamp ofclaim 1, wherein the passive tracking device is coupled to one of thefirst surface and the second surface.
 7. The postage stamp of claim 1,wherein the stamp identification (ID) information is unique to eachstamp. 8-10. (canceled)
 11. A postage stamp dispensing systemcomprising: a plurality of postage stamps, each stamp including atracking device that includes stamp ID information; a stamp dispenseradapted to contain and dispense the stamps; a reader operativelyassociated with the stamp dispenser to read the stamp ID informationwhen the relative position between the stamp and the reader changes asthe stamp is dispensed; and a database operable to store the read stampID information, wherein each tracking device includes a radio frequencyidentification (RFID) device that does not include an onboard powersupply, and wherein the RFID device is passive.
 12. The system of claim11, wherein the stamp ID information includes encrypted datacorresponding to at least two of a date, a location, a postage value,and a unique designation.
 13. The postage stamp of claim 12, whereinencrypted data are combined to at least partially yield the stamp IDinformation.
 14. The system of claim 13, wherein the encrypted data thatmakes up the stamp ID information is stored as separate values in thedatabase.
 15. The system of claim 12, wherein the dispenser is a vendingmachine and the device reader is part of the vending machine.
 16. Thesystem of claim 12, wherein a portion of the plurality of stamps arearranged in a book and the book includes book identification data. 17.The system of claim 16, wherein the reader is operable to read the bookidentification data and the database is operable to store the bookidentification data.
 18. The system of claim 11, further comprising animaging device operatively associated with the stamp dispenser tocapture an image of the user of the stamp dispenser.
 19. A method oftracking a postage stamp, the method comprising: coupling trackinginformation to the stamp, the tracking information including a stamp ID;dispensing the stamp to a customer; reading the tracking information asthe stamp is dispensed; and storing the stamp ID in a database, whereinthe tracking information is stored within a passive RFID device thatdoes not include an onboard power supply.
 20. The method of claim 19,further comprising capturing an image of the customer and storing thecaptured image in the database.
 21. (canceled)
 22. The method of claim19, further comprising storing a dispensing location within thedatabase.
 23. The method of claim 19, further comprising reading thetracking information as the stamp is deposited into a postal mailbox,and storing the stamp ID and a mailbox location within a database. 24.The method of claim 23, further comprising comparing the mailboxlocation and the dispensing location, and identifying the stamp if themailbox location is more than a predefined distance from the dispensinglocation.
 25. The method of claim 19, further comprising sensing when anarticle is deposited in a mailbox; determining when tracking informationwas not properly read for all the articles placed in the mailbox; andproviding a perceivable indication when it has been determined thattracking information was not properly read for all the articles placedin the mailbox.
 26. The method of claim 19, wherein the dispensing stepincludes dispensing the stamp as part of a book of stamps, and whereinthe book includes book identification information.
 27. The method ofclaim 26, wherein the reading step also includes reading the bookidentification information, and the storing step also includes storingthe book ID in the database.
 28. The method of claim 27, wherein thedatabase includes a list of individual stamp IDs associated with thebook ID.